During apoptosis, the Golgi complex becomes fragmented and key proteins (e.g., GRASP65 and p 115) are targets for caspase cleavage. GM 130, an integral membrane protein, contributes to the maintenance of Golgi structure and facilitates membrane fusion with secretory vesicles. We show that GM130 levels decrease during Fas-induced apoptosis but not during staurosporine-induced apoptosis while in both models p115 levels remain unaffected. We conclude that GM130 is rapidly diminished during Fas-mediated apoptosis associated with Golgi fragmentation in contrast to previous studies which have suggested that loss of GM130 during apoptosis is a late event. (C) 2004 Elsevier Inc. All rights reserved.